CN112458373B - Casting material for guide sliding shoes of coal mining machine and preparation method - Google Patents

Casting material for guide sliding shoes of coal mining machine and preparation method Download PDF

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CN112458373B
CN112458373B CN202011343917.3A CN202011343917A CN112458373B CN 112458373 B CN112458373 B CN 112458373B CN 202011343917 A CN202011343917 A CN 202011343917A CN 112458373 B CN112458373 B CN 112458373B
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quenching
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casting
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CN112458373A (en
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陈杰华
张文琦
刘国强
魏靖奇
高宇
邵新波
左丽萍
段善龙
王聪
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Zhengzhou Coal Machinery Intelligent Working Face Technology Co ltd
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Zhengzhou Coal Machinery Intelligent Working Face Technology Co ltd
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/06—Surface hardening
    • C21D1/09—Surface hardening by direct application of electrical or wave energy; by particle radiation
    • C21D1/10—Surface hardening by direct application of electrical or wave energy; by particle radiation by electric induction
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/18—Hardening; Quenching with or without subsequent tempering
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/26—Methods of annealing
    • C21D1/28—Normalising
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D11/00—Process control or regulation for heat treatments
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2261/00—Machining or cutting being involved
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
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Abstract

The invention discloses a casting material for a guide sliding shoe of a coal mining machine and a preparation method thereof, wherein the casting material comprises the following formula components in percentage by weight: 0.35-0.45% of C, 0.45-0.7% of Mn0.25-0.6% of Si, less than or equal to 0.03% of P, less than or equal to 0.03% of S, less than or equal to 0.9-1.4% of Cr0.9, 0.25-0.35% of Mo0, 1.3-1.8% of Ni1, less than or equal to 0.04% of Al, less than or equal to 0.25% of Cu, less than or equal to 0.1% of V and the balance of Fe.

Description

Casting material for guide sliding shoes of coal mining machine and preparation method
Technical Field
The invention relates to the technical field of fully mechanized mining equipment, in particular to a casting material for a guide sliding shoe of a coal mining machine and a preparation method thereof.
Background
The guide sliding shoe is one of the main parts of the coal mining machine, and the quality stability of the guide sliding shoe directly determines the comprehensive quality of the coal mining machine. The guide groove of the guide sliding shoe bears large bending load along with the up-and-down fluctuation of the coal face and the left-and-right bending of the chute, and uncertainty exists between the load position and the load direction. Meanwhile, the working conditions of the coal face are extremely harsh, coal dust can be used as abrasive materials to increase abrasion, and in addition, the guide face of the guide sliding shoe can generate great friction with the chute along with the walking of the coal mining machine, so that the guide face is seriously abraded.
At present, the hardening process of the guide surface of the guide sliding shoe mainly adopts medium-frequency induction quenching and is limited by factors such as structure, process and the like, and quenching cracks always puzzle the important problem of the guide sliding shoe hardening. Some coal mills have up to hundreds of guide shoes scrapped each year due to quench cracking, resulting in large economic losses. Meanwhile, part of coal mining machines companies adopt welding wear plates to replace induction quenching, so that the guide sliding shoes are poor in wear resistance, complex to operate, prone to secondary defects and poor in stability.
Disclosure of Invention
The inventor summarizes in long-term practice: the reasons for the occurrence of quenching cracks in the intermediate frequency induction quenching process of the guide sliding shoe mainly comprise: 1. sharp corner effect cracks, and processing before quenching is not carried out; 2. casting defects; 3. induction quenching process and improper operation including process parameters, part structure, cooling medium and other factors; 4. the quenching tool is complex and heavy, and the quenching tool is not matched with the quenching machine tool; 5. the invention provides a casting material for a guide sliding shoe of a coal mining machine and a preparation method thereof, aiming at preventing quenching cracks from occurring due to the fact that a section of part is left without quenching due to the fact that quenching cracks are feared.
In order to achieve the purpose, the invention provides the following technical scheme:
the casting material for the guide sliding shoe of the coal mining machine comprises the following formula components in percentage by weight:
0.35 to 0.45 percent of C, 0.45 to 0.7 percent of Mn0.25 to 0.6 percent of Si, less than or equal to 0.03 percent of P, less than or equal to 0.03 percent of S, 0.9 to 1.4 percent of Cr0.25 to 0.35 percent of Mo0.3 to 1.8 percent of Ni1.3, less than or equal to 0.04 percent of Al, less than or equal to 0.25 percent of Cu, less than or equal to 0.1 percent of V, and the balance of Fe;
the carbon equivalent is CE, and CE is C + Mn/6+ (Cr + Mo + V)/5+ (Ni + Cu)/15 is less than or equal to 0.91 percent.
Further, the formula comprises the following components in percentage by weight:
0.4% of C, 0.55% of Mn0.42% of Si0.42%, 0.03% of P, 0.02% of S, 1.2% of Cr1.3%, 0.3% of Mo0.55% of Ni1.04%, 0.2% of Al0.2%, 0.1% of V and the balance of Fe.
The invention also provides a preparation method of the casting material for the guide sliding shoe of the coal mining machine, which comprises the following steps:
s1, smelting:
according to the formula components and carbon equivalent of the casting material, putting the formula raw materials into a smelting furnace, and smelting to obtain molten steel;
s2, casting:
manufacturing a mould, pouring and casting to obtain a casting, carrying out nondestructive inspection on the casting, and obtaining a standard for inspection acceptance: the guide rail surface (i.e. quenching surface) area is level 1, the rest parts are level 2, and the casting grain size requirement is more than or equal to level 5;
s3, heat treatment:
cutting a casting head, performing normalizing and primary tempering treatment at the normalizing temperature of 880-;
s4, hardening and tempering:
adopting a quenching and secondary tempering mode, wherein the quenching temperature is 850-;
s5, processing before quenching:
chamfering a first fillet at the intersection of the quenching surface and the non-quenching surface to avoid the sharp angle effect of induction quenching, processing the quenching surface until the surface roughness is not higher than Ra6.3, processing an inner chamfer between the adjacent quenching surfaces, and chamfering a second fillet at the intersection of the casting non-processing surface and the processing surface (the casting non-processing surface refers to the surface directly formed by casting, and the processing surface does not need to be processed in the later period;
s6, induction quenching and third tempering treatment:
s61, installing the quenching tool and the quenching inductor on a quenching machine tool, and then installing a blank to ensure that the verticality of the blank is less than or equal to 0.5 mm;
s62, adjusting the gap between the quenching inductor and each quenching surface of the blank to ensure the uniform gap;
s63, detecting the concentration and the temperature of the quenching medium, ensuring that the effluent pressure is adjusted to the range of the process requirement within the range of the process requirement, opening a valve, and detecting the water spraying condition;
s64, trial run in no-load mode, and move the quenching machine tool up and down to ensure that the quenching inductor and the quenching surfaces have consistent upper and lower gaps and the quenching machine tool runs stably;
s65, performing medium-frequency induction quenching and third tempering on the blank;
s7, finishing, performing rust prevention treatment and packaging.
Further, adopting a smelting mode of smelting in an electric arc furnace or a converter and refining outside an LF furnace.
Further, referring to requirements in JB/T5000.14-2007 nondestructive inspection of steel castings under general technical conditions for heavy machinery, nondestructive inspection methods and acceptance standards (including UT, PT and MT) of castings, and inspection acceptance standards: the guide rail surface area is 1 grade, and the rest parts are 2 grades; the grain size requirement of the casting is more than or equal to grade 5, the quality of the casting material is improved, and a good foundation is laid for the stable quality of the subsequent induction quenching.
Further, after step S3, rough machining including the steps of sand blasting, cleaning, polishing, etc. is performed, and after the rough machining, ultrasonic flaw detection is performed mainly for detecting defects in the heat treatment process.
Further, after step S4, magnetic powder inspection or dye flaw detection is performed, and cracks are not allowed to appear, mainly for the purpose of inspecting defects during the thermal refining.
Further, in step S5, the radius of the first fillet is not less than 2mm, the radius of the inner chamfer is 3-5mm, and the radius of the second fillet is not less than 8 mm. By increasing the requirement of processing before induction quenching, the structure of the quenching surface and the structure of the relevant part are optimized, and the possibility of heat treatment quenching cracks caused by structural reasons is avoided to the greatest extent.
Further, before step S6, performing once penetrant inspection on the quenching surface, not allowing the existence of defects such as cracks that affect the quenching quality, and further identifying the state of the quenching surface before induction quenching, so as to avoid the influence of defects existing in the aspects of casting, rough machining, heat treatment, thermal refining and the like on the induction quenching quality.
Preferably, the flaw detection before induction quenching not only provides early-stage condition analysis and prejudgment for subsequent induction quenching, but also can carry out necessary treatment on the problems, thereby avoiding the occurrence of later-stage heat treatment defects.
Further, in step S6, according to the guide shoe size required by the drawing, determining the size of a quenching sensor, wherein the quenching sensor is a continuous quenching spray cooling sensor, adopts a double-layer structure and comprises a heating layer and a cooling layer, the heating layer is provided with a magnetizer for heating a quenching surface, the cooling layer is provided with an inclined plane as a water spraying surface, the water spraying surface is provided with water spraying holes with the diameter of 0.8-1.5mm, the water spraying surface and the quenching surface form an included angle of 45-55 degrees, and the gap between the quenching sensor and the quenching surface is 1-4 mm.
Further, in step S6, the quenching frock is used for fixing the blank on quenching machine tool, the quenching frock includes support, otic placode and base, and otic placode, base all link firmly with the support, be equipped with the mounting hole on the otic placode, and the otic placode of blank and mounting hole pass through the connecting rod and link firmly, the base is used for with the quenching lathe, simultaneously, be equipped with the support that terminal and blank lateral wall offset on the support and push away the bolt, prevent that the blank from rotating around the connecting rod, make the blank keep vertical state carry out subsequent intermediate frequency induction hardening operation.
Preferably, the best condition as possible is created for the guide sliding shoe induction quenching process by optimizing the structures of the quenching inductor and the quenching tool.
Further, in step S6, a continuous heating quenching method is adopted, heating and cooling are carried out simultaneously, the power supply power is 250-270kW, the frequency is 2-8KHz, the input voltage is 380-400V, the current is 50-70A, the moving speed of a quenching machine tool is 1-1.5mm/S, the time delay is 2S after heating is started, PAG water-soluble quenching medium is adopted for cooling, the medium concentration is 10-12%, the temperature of the cooling medium is 20-40 ℃, the cooling mode is spray cooling, the water spray pressure is 0.35MPa, the third tempering temperature is 220 +/-10 ℃, and the third tempering time is not less than 5 h.
The inventor accumulates a large amount of empirical data through repeated tests, optimizes induction quenching parameters and third tempering parameters, and provides reliable guarantee for the stable quality and the improvement of the induction quenching of the guide sliding shoe.
Further, after step S6, secondary penetrant inspection is performed on the quenched surface, and the quenched cracks are not allowed to appear.
The invention has the beneficial effects that:
1. the method has the advantages that nondestructive flaw detection is carried out on the casting, the material quality of the casting is improved, a good foundation is laid for the stability of the subsequent induction quenching quality, meanwhile, the possibility of heat treatment quenching cracks caused by structural reasons is avoided to the greatest extent by increasing the requirements of processing before induction quenching and the structures of a quenching surface and a non-quenching surface, and in addition, the best possible conditions are created for the guide sliding shoe induction quenching process by optimizing the structures of a quenching inductor and a quenching tool.
2. The flaw detection before induction quenching not only provides early-stage condition analysis and prejudgment for subsequent induction quenching, but also can carry out necessary treatment on the problems, so that the defects of later-stage heat treatment are avoided.
Drawings
FIG. 1 is a schematic structural view of a quench inductor;
FIG. 2 is a schematic view of the location of the first fillet and the inner fillet;
figure 3 is a schematic view of the location of the second rounded corner.
In the drawings: 1-quenching surface, 2-quenching inductor, 3-heating layer, 4-cooling layer, 5-water spraying surface, 6-first fillet, 7-inner chamfer and 8-second fillet.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The first embodiment is as follows:
the casting material for the guide sliding shoe of the coal mining machine comprises the following formula components in percentage by weight:
0.35% of C, 0.45% of Mn0.25% of Si, 0.015% of P, 0.02% of S, 0.9% of Cr0.25% of Mo0.25% of Ni, 0.02% of Al, 0.015% of Cu0.08% of V, and the balance of Fe;
the carbon equivalent is CE, and CE is C + Mn/6+ (Cr + Mo + V)/5+ (Ni + Cu)/15 is less than or equal to 0.91 percent.
The preparation method of the casting material for the guide sliding shoe of the coal mining machine comprises the following steps:
s1, smelting:
according to the formula components and the carbon equivalent of the casting material, the formula raw materials are put into a smelting furnace, and are smelted in a smelting mode of smelting in an electric arc furnace or a converter and refining outside an LF furnace to obtain molten steel.
S2, casting:
making a mould, pouring, casting to obtain a casting, and carrying out nondestructive inspection on the casting according to requirements in JB/T5000.14-2007 nondestructive inspection of steel casting under general technical conditions for heavy machinery, nondestructive inspection methods and acceptance standards (including UT, PT and MT) and inspection acceptance standards: the guide rail surface area is 1 grade, and the rest parts are 2 grades; the grain size requirement of the casting is more than or equal to grade 5, the quality of the casting material is improved, and a good foundation is laid for the stable quality of the subsequent induction quenching.
S3, heat treatment:
cutting a casting head, normalizing and performing first tempering treatment, wherein the normalizing temperature is 880 ℃, the heat preservation time is more than or equal to 5 hours, discharging from a furnace, air cooling, the first tempering temperature is 600 ℃, the heat preservation time is more than or equal to 8 hours, and discharging from the furnace, air cooling.
And S4, performing rough machining, including the procedures of sand blasting, cleaning, grinding and the like, and performing ultrasonic flaw detection after the rough machining is finished, wherein the ultrasonic flaw detection is mainly used for detecting defects in the heat treatment process.
S5, hardening and tempering:
adopting a quenching and secondary tempering mode, wherein the quenching temperature is 850 ℃, the heat preservation time is more than or equal to 4 hours, discharging from the furnace, cooling by oil or by PAG water-based quenching medium, the secondary tempering temperature is 610 ℃, the heat preservation time is more than or equal to 6 hours, and discharging from the furnace, cooling by air.
S6, magnetic powder or dye inspection, wherein cracks are not allowed to appear, and the defects in the quenching and tempering process are mainly inspected.
S7, processing before quenching:
as shown in fig. 2 and 3, a first fillet 6 is chamfered at the intersection of the quenching surface and the non-quenching surface, the radius of the first fillet 6 is not less than 2mm, the quenching surface is machined until the surface roughness of the quenching surface is not higher than Ra6.3, an inner chamfer 7 is machined between the adjacent quenching surfaces, the radius of the inner chamfer 7 is 3mm, a second fillet 8 is chamfered at the intersection of the casting non-machining surface and the machining surface, and the radius of the second fillet 8 is not less than 8mm, so that a blank is obtained. By increasing the requirement of processing before induction quenching, the structure of the quenching surface and the structure of the relevant part are optimized, and the possibility of heat treatment quenching cracks caused by structural reasons is avoided to the greatest extent.
S8, carrying out primary penetrant inspection on the quenching surface, not allowing the defects such as cracks and the like which affect the quenching quality, further identifying the state of the quenching surface before induction quenching, and avoiding the defects existing in the aspects of casting, rough machining, heat treatment, quenching and tempering and the like from affecting the induction quenching quality. The flaw detection before induction quenching not only provides early-stage condition analysis and prejudgment for subsequent induction quenching, but also can carry out necessary treatment on the problems, thereby avoiding the occurrence of later-stage heat treatment defects.
S9, induction quenching and third tempering treatment:
installing a quenching tool and a quenching inductor on a quenching machine tool, installing a blank again, ensuring that the verticality of the blank is less than or equal to 0.5mm, adjusting the gap between the quenching inductor and each quenching surface of the blank, ensuring that the gap is uniform, detecting the concentration and the temperature of a quenching medium, ensuring that the water outlet pressure is adjusted to the range of the process requirement within the range of the process requirement, opening a valve, detecting the water spraying condition, carrying out no-load trial run, moving the quenching machine tool up and down, ensuring that the upper and lower gaps of the quenching inductor and each quenching surface are consistent, and stably operating the quenching machine tool, and carrying out medium-frequency induction quenching and third tempering treatment on the blank.
As shown in figure 1, according to the direction piston shoe size that the drawing required, confirm quenching inductor 2 size, quenching inductor 2 is continuous quenching spray cooling inductor, adopts bilayer structure, including zone of heating 3 and cooling layer 4, the zone of heating 3 is equipped with the magnetizer for quenching face 1 heats, cooling layer 4 is processed to have the inclined plane as the water spray face 5, and water spray face 5 is processed to have the diameter to be 0.8mm hole for water spray, and water spray face 5 is 45 contained angles with quenching face 1, and spun water can reach quenching face 1 when guaranteeing the induction hardening, and simultaneously, the clearance of quenching inductor and quenching face is 1 mm. The quenching tool is used for fixing the blank on a quenching machine tool, the quenching tool comprises a support, an ear plate and a base, the ear plate and the base are fixedly connected with the support, a mounting hole is formed in the ear plate, the ear hole of the blank is fixedly connected with the mounting hole through a connecting rod, the base is used for being connected with the quenching machine tool, meanwhile, a pushing bolt which is abutted against the side wall of the blank at the tail end is arranged on the support, the blank is prevented from rotating around the connecting rod, and the blank is kept in a vertical state to perform subsequent intermediate frequency induction quenching operation. By optimizing the structures of the quenching inductor and the quenching tool, the best condition as possible is created for the guide sliding shoe induction quenching process.
The inventor accumulates a large amount of empirical data through repeated tests, optimizes induction quenching parameters and third tempering parameters, and provides reliable guarantee for the stable quality and the improvement of the induction quenching of the guide sliding shoe. Specifically, a continuous heating quenching method is adopted, heating and cooling are carried out simultaneously, the power supply power is 250kW, the frequency is 2KHz, the input voltage is 380V, the current is 50A, the moving speed of a quenching machine tool is 1mm/s, the time delay is 2s after the heating is started, PAG water-soluble quenching medium is adopted for cooling, the medium concentration is 10%, the temperature of the cooling medium is 20 ℃, the cooling mode is spray cooling, the water spray pressure is 0.35MPa, the third tempering temperature is 210 ℃, and the third tempering time is not less than 5 h.
And S10, carrying out secondary penetrant inspection on the quenching surface, wherein no quenching crack appears.
And S11, finishing to meet the requirement of drawing size, performing rust prevention treatment, and packaging.
Example two:
the casting material for the guide sliding shoe of the coal mining machine comprises the following formula components in percentage by weight:
0.4% of C, 0.55% of Mn0.42% of Si0.42%, 0.03% of P, 0.02% of S, 1.2% of Cr1.3%, 0.3% of Mo0.55% of Ni1.04%, 0.2% of Al0.2%, 0.1% of V and the balance of Fe.
The preparation method of the casting material for the guide sliding shoe of the coal mining machine comprises the following steps:
s1, smelting:
according to the formula components and the carbon equivalent of the casting material, the formula raw materials are put into a smelting furnace, and are smelted in a smelting mode of smelting in an electric arc furnace or a converter and refining outside an LF furnace to obtain molten steel.
S2, casting:
making a mould, pouring, casting to obtain a casting, and carrying out nondestructive inspection on the casting according to requirements in JB/T5000.14-2007 nondestructive inspection of steel casting under general technical conditions for heavy machinery, nondestructive inspection methods and acceptance standards (including UT, PT and MT) and inspection acceptance standards: the guide rail surface area is 1 grade, and the rest parts are 2 grades; the grain size requirement of the casting is more than or equal to grade 5, the quality of the casting material is improved, and a good foundation is laid for the stable quality of the subsequent induction quenching.
S3, heat treatment:
cutting a casting head, carrying out normalizing and first tempering treatment, discharging from a furnace, air-cooling, carrying out first tempering at the temperature of 890 ℃, keeping the temperature for more than or equal to 5h, and discharging from the furnace, carrying out air-cooling, wherein the first tempering temperature is 630 ℃, the keeping temperature for more than or equal to 8h, and discharging from the furnace, and carrying out air-cooling.
And S4, performing rough machining, including the procedures of sand blasting, cleaning, grinding and the like, and performing ultrasonic flaw detection after the rough machining is finished, wherein the ultrasonic flaw detection is mainly used for detecting defects in the heat treatment process.
S5, hardening and tempering:
adopting a quenching and secondary tempering mode, wherein the quenching temperature is 860 ℃, the heat preservation time is more than or equal to 4 hours, discharging from the furnace, cooling by oil or by PAG water-based quenching medium, the secondary tempering temperature is 620 ℃, the heat preservation time is more than or equal to 6 hours, and discharging from the furnace, and cooling by air.
S6, magnetic powder or dye inspection, wherein cracks are not allowed to appear, and the defects in the quenching and tempering process are mainly inspected.
S7, processing before quenching:
and chamfering a first fillet 6 at the intersection of the quenching surface and the non-quenching surface, wherein the radius of the first fillet 6 is not less than 2mm, machining the quenching surface until the surface roughness is not higher than Ra6.3, machining an inner chamfer 7 between the adjacent quenching surfaces, wherein the radius of the inner chamfer 7 is 4mm, chamfering a second fillet 8 at the intersection of the casting non-machining surface and the machining surface, and the radius of the second fillet 8 is not less than 8mm, thus obtaining a blank. By increasing the requirement of processing before induction quenching, the structure of the quenching surface and the structure of the relevant part are optimized, and the possibility of heat treatment quenching cracks caused by structural reasons is avoided to the greatest extent.
S8, carrying out primary penetrant inspection on the quenching surface, not allowing the defects such as cracks and the like which affect the quenching quality, further identifying the state of the quenching surface before induction quenching, and avoiding the defects existing in the aspects of casting, rough machining, heat treatment, quenching and tempering and the like from affecting the induction quenching quality. The flaw detection before induction quenching not only provides early-stage condition analysis and prejudgment for subsequent induction quenching, but also can carry out necessary treatment on the problems, thereby avoiding the occurrence of later-stage heat treatment defects.
S9, induction quenching and third tempering treatment:
installing a quenching tool and a quenching inductor on a quenching machine tool, installing a blank again, ensuring that the verticality of the blank is less than or equal to 0.5mm, adjusting the gap between the quenching inductor and each quenching surface of the blank, ensuring that the gap is uniform, detecting the concentration and the temperature of a quenching medium, ensuring that the water outlet pressure is adjusted to the range of the process requirement within the range of the process requirement, opening a valve, detecting the water spraying condition, carrying out no-load trial run, moving the quenching machine tool up and down, ensuring that the upper and lower gaps of the quenching inductor and each quenching surface are consistent, and stably operating the quenching machine tool, and carrying out medium-frequency induction quenching and third tempering treatment on the blank.
The water spraying surface 5 is provided with a water spraying hole with the diameter of 1.2mm, the water spraying surface 5 and the quenching surface 1 form an included angle of 50 degrees, and the gap between the quenching inductor 2 and the quenching surface 1 is 3 mm. The quenching tool is used for fixing the blank on a quenching machine tool, the quenching tool comprises a support, an ear plate and a base, the ear plate and the base are fixedly connected with the support, a mounting hole is formed in the ear plate, the ear hole of the blank is fixedly connected with the mounting hole through a connecting rod, the base is used for being connected with the quenching machine tool, meanwhile, a pushing bolt which is abutted against the side wall of the blank at the tail end is arranged on the support, the blank is prevented from rotating around the connecting rod, and the blank is kept in a vertical state to perform subsequent intermediate frequency induction quenching operation. By optimizing the structures of the quenching inductor and the quenching tool, the best condition as possible is created for the guide sliding shoe induction quenching process.
The inventor accumulates a large amount of empirical data through repeated tests, optimizes induction quenching parameters and third tempering parameters, and provides reliable guarantee for the stable quality and the improvement of the induction quenching of the guide sliding shoe. Specifically, a continuous heating quenching method is adopted, heating and cooling are carried out simultaneously, the power supply power is 260kW, the frequency is 5KHz, the input voltage is 390V, the current is 60A, the moving speed of a quenching machine tool is 1.2mm/s, the time delay is 2s after heating is started, PAG water-soluble quenching medium is adopted for cooling, the medium concentration is 11%, the temperature of the cooling medium is 30 ℃, the cooling mode is spray cooling, the water spray pressure is 0.35MPa, the third tempering temperature is 220 ℃, and the third tempering time is not less than 5 h.
And S10, carrying out secondary penetrant inspection on the quenching surface, wherein no quenching crack appears.
And S11, finishing to meet the requirement of drawing size, performing rust prevention treatment, and packaging.
Example three:
the casting material for the guide sliding shoe of the coal mining machine comprises the following formula components in percentage by weight:
0.45% of C, 0.7% of Mn0.6% of Si, 0.03% of P, 0.03% of S, 1.4% of Cr1.4%, 0.35% of Mo0.8% of Ni1.8%, 0.04% of Al0.25% of Cu0.1%, and the balance of Fe;
the carbon equivalent is CE, and CE is C + Mn/6+ (Cr + Mo + V)/5+ (Ni + Cu)/15 is less than or equal to 0.91 percent.
The preparation method of the casting material for the guide sliding shoe of the coal mining machine comprises the following steps:
s1, smelting:
according to the formula components and the carbon equivalent of the casting material, the formula raw materials are put into a smelting furnace, and are smelted in a smelting mode of smelting in an electric arc furnace or a converter and refining outside an LF furnace to obtain molten steel.
S2, casting:
making a mould, pouring, casting to obtain a casting, and carrying out nondestructive inspection on the casting according to requirements in JB/T5000.14-2007 nondestructive inspection of steel casting under general technical conditions for heavy machinery, nondestructive inspection methods and acceptance standards (including UT, PT and MT) and inspection acceptance standards: the guide rail surface area is 1 grade, and the rest parts are 2 grades; the grain size requirement of the casting is more than or equal to grade 5, the quality of the casting material is improved, and a good foundation is laid for the stable quality of the subsequent induction quenching.
S3, heat treatment:
cutting a casting head, carrying out normalizing and first tempering treatment, discharging from a furnace, air-cooling, carrying out first tempering at the temperature of 900 ℃ for more than or equal to 5h, and discharging from the furnace, carrying out air-cooling, carrying out first tempering at the temperature of 650 ℃ for more than or equal to 8h, and carrying out discharging from the furnace, air-cooling.
And S4, performing rough machining, including the procedures of sand blasting, cleaning, grinding and the like, and performing ultrasonic flaw detection after the rough machining is finished, wherein the ultrasonic flaw detection is mainly used for detecting defects in the heat treatment process.
S5, hardening and tempering:
adopting a quenching and secondary tempering mode, wherein the quenching temperature is 870 ℃, the heat preservation time is more than or equal to 4 hours, discharging from the furnace, cooling by oil or PAG water-based quenching medium, the secondary tempering temperature is 630 ℃, the heat preservation time is more than or equal to 6 hours, and discharging from the furnace, cooling by air.
S6, magnetic powder or dye inspection, wherein cracks are not allowed to appear, and the defects in the quenching and tempering process are mainly inspected.
S7, processing before quenching:
and chamfering a first fillet 6 at the intersection of the quenching surface and the non-quenching surface, wherein the radius of the first fillet 6 is not less than 2mm, machining the quenching surface until the surface roughness is not higher than Ra6.3, machining an inner chamfer 7 between the adjacent quenching surfaces, wherein the radius of the inner chamfer 7 is 5mm, chamfering a second fillet 8 at the intersection of the casting non-machining surface and the machining surface, and the radius of the second fillet 8 is not less than 8mm, thus obtaining a blank. By increasing the requirement of processing before induction quenching, the structure of the quenching surface and the structure of the relevant part are optimized, and the possibility of heat treatment quenching cracks caused by structural reasons is avoided to the greatest extent.
S8, carrying out primary penetrant inspection on the quenching surface, not allowing the defects such as cracks and the like which affect the quenching quality, further identifying the state of the quenching surface before induction quenching, and avoiding the defects existing in the aspects of casting, rough machining, heat treatment, quenching and tempering and the like from affecting the induction quenching quality. The flaw detection before induction quenching not only provides early-stage condition analysis and prejudgment for subsequent induction quenching, but also can carry out necessary treatment on the problems, thereby avoiding the occurrence of later-stage heat treatment defects.
S9, induction quenching and third tempering treatment:
installing a quenching tool and a quenching inductor on a quenching machine tool, installing a blank again, ensuring that the verticality of the blank is less than or equal to 0.5mm, adjusting the gap between the quenching inductor and each quenching surface of the blank, ensuring that the gap is uniform, detecting the concentration and the temperature of a quenching medium, ensuring that the water outlet pressure is adjusted to the range of the process requirement within the range of the process requirement, opening a valve, detecting the water spraying condition, carrying out no-load trial run, moving the quenching machine tool up and down, ensuring that the upper and lower gaps of the quenching inductor and each quenching surface are consistent, and stably operating the quenching machine tool, and carrying out medium-frequency induction quenching and third tempering treatment on the blank.
The water spraying surface 5 is provided with a water spraying hole with the diameter of 1.5mm, the water spraying surface 5 and the quenching surface 1 form an included angle of 55 degrees, and the gap between the quenching inductor 2 and the quenching surface 1 is 4 mm. The quenching tool is used for fixing the blank on a quenching machine tool, the quenching tool comprises a support, an ear plate and a base, the ear plate and the base are fixedly connected with the support, a mounting hole is formed in the ear plate, the ear hole of the blank is fixedly connected with the mounting hole through a connecting rod, the base is used for being connected with the quenching machine tool, meanwhile, a pushing bolt which is abutted against the side wall of the blank at the tail end is arranged on the support, the blank is prevented from rotating around the connecting rod, and the blank is kept in a vertical state to perform subsequent intermediate frequency induction quenching operation. By optimizing the structures of the quenching inductor and the quenching tool, the best condition as possible is created for the guide sliding shoe induction quenching process.
The inventor accumulates a large amount of empirical data through repeated tests, optimizes induction quenching parameters and third tempering parameters, and provides reliable guarantee for the stable quality and the improvement of the induction quenching of the guide sliding shoe. Specifically, a continuous heating quenching method is adopted, heating and cooling are carried out simultaneously, the power supply power is 270kW, the frequency is 8KHz, the input voltage is 400V, the current is 70A, the moving speed of a quenching machine tool is 1.5mm/s, the time delay is 2s after heating is started, PAG water-soluble quenching medium is adopted for cooling, the medium concentration is 12%, the temperature of the cooling medium is 40 ℃, the cooling mode is spray cooling, the water spray pressure is 0.35MPa, the third tempering temperature is 230 ℃, and the third tempering time is not less than 5 h.
And S10, carrying out secondary penetrant inspection on the quenching surface, wherein no quenching crack appears.
And S11, finishing to meet the requirement of drawing size, performing rust prevention treatment, and packaging.
Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims (5)

1. The casting material for the guide sliding shoe of the coal mining machine is characterized by comprising the following formula components in percentage by weight:
0.35 to 0.45 percent of C, 0.45 to 0.7 percent of Mn0.25 to 0.6 percent of Si, less than or equal to 0.03 percent of P, less than or equal to 0.03 percent of S, 0.9 to 1.4 percent of Cr0.25 to 0.35 percent of Mo0.3 to 1.8 percent of Ni1.3, less than or equal to 0.04 percent of Al, less than or equal to 0.25 percent of Cu, less than or equal to 0.1 percent of V, and the balance of Fe;
the carbon equivalent is CE, and CE is C + Mn/6+ (Cr + Mo + V)/5+ (Ni + Cu)/15 is less than or equal to 0.91 percent;
the method for preparing the guide sliding shoe of the coal mining machine by using the guide sliding shoe casting material of the coal mining machine comprises the following steps:
s1, smelting:
according to the formula components and carbon equivalent of the casting material, putting the formula raw materials into a smelting furnace, and smelting to obtain molten steel;
s2, casting:
manufacturing a mould, pouring and casting to obtain a casting, carrying out nondestructive inspection on the casting, and obtaining a standard for inspection acceptance: the guide rail surface area is 1 grade, the rest parts are 2 grades, and the grain size requirement of the casting is more than or equal to 5 grades;
s3, heat treatment:
cutting a casting head, performing normalizing and primary tempering treatment at the normalizing temperature of 880-;
s4, hardening and tempering:
adopting a quenching and secondary tempering mode, wherein the quenching temperature is 850-;
s5, processing before quenching:
chamfering a first fillet at the intersection of the quenching surface and the non-quenching surface until the surface roughness of the quenching surface is not higher than Ra6.3, machining an inner chamfer between the adjacent quenching surfaces, chamfering a second fillet at the intersection of the cast non-machining surface and the machining surface to obtain a blank, wherein the radius of the first fillet is not less than 2mm, the radius of the inner chamfer is 3-5mm, and the radius of the second fillet is not less than 8 mm;
s6, induction quenching and third tempering treatment:
s61, installing the quenching tool and the quenching inductor on a quenching machine tool, and then installing a blank to ensure that the verticality of the blank is less than or equal to 0.5 mm;
determining the size of a quenching inductor according to the size of a guide sliding shoe required by a drawing, wherein the quenching inductor is a continuous quenching spray cooling inductor and adopts a double-layer structure, and comprises a heating layer and a cooling layer, the heating layer is provided with a magnetizer for heating a quenching surface, the cooling layer is provided with an inclined surface as a water spraying surface, the water spraying surface is provided with water spraying holes with the diameter of 0.8-1.5mm, and the water spraying surface and the quenching surface form an included angle of 45-55 degrees;
the quenching tool comprises a support, an ear plate and a base, wherein the ear plate and the base are fixedly connected with the support, the ear plate is provided with a mounting hole, the ear hole of the blank is fixedly connected with the mounting hole through a connecting rod, the base is used for the quenching machine tool, and the support is provided with a pushing bolt with the tail end abutting against the side wall of the blank;
s62, adjusting the gap between the quenching inductor and each quenching surface of the blank to ensure the uniform gap;
s63, detecting the concentration and the temperature of the quenching medium, ensuring that the effluent pressure is adjusted to the range of the process requirement within the range of the process requirement, opening a valve, and detecting the water spraying condition;
s64, trial run in no-load mode, and move the quenching machine tool up and down to ensure that the quenching inductor and the quenching surfaces have consistent upper and lower gaps and the quenching machine tool runs stably;
s65, performing medium-frequency induction quenching and third tempering on the blank;
heating and cooling are carried out simultaneously by adopting a continuous heating and quenching method, the power supply power is 250-270kW, the frequency is 2-8KHz, the input voltage is 380-400V, the current is 50-70A, the moving speed of a quenching machine tool is 1-1.5mm/s, the time delay is 2s after heating is started, PAG water-soluble quenching medium is adopted for cooling, the medium concentration is 10-12%, the temperature of the cooling medium is 20-40 ℃, the cooling mode is spray cooling, the water spray pressure is 0.35MPa, the third tempering temperature is 220 +/-10 ℃, and the third tempering time is not less than 5 h;
s7, finishing, performing rust prevention treatment and packaging.
2. The shearer guide shoe casting material as claimed in claim 1, comprising the following formulation components in weight percent:
0.4% of C, 0.55% of Mn0.42% of Si0.42%, 0.03% of P, 0.02% of S, 1.2% of Cr1.3%, 0.3% of Mo0.55% of Ni1.04%, 0.2% of Al0.2%, 0.1% of V and the balance of Fe.
3. The shearer guide shoe casting material according to claim 1 or 2, wherein a gap between the quenching inductor and the quenching surface is 1 to 4 mm.
4. The shearer guide shoe casting material according to claim 3, wherein the step S3 is followed by rough machining including sand blasting, cleaning, and grinding, and after the rough machining is finished, ultrasonic flaw detection is performed to detect defects during heat treatment.
5. The shearer guide shoe casting material of claim 4, wherein step S6 is preceded by a primary penetrant inspection of the quenching surface, which does not allow defects affecting the quenching quality, and step S6 is followed by a secondary penetrant inspection of the quenching surface, which does not allow quench cracks to develop.
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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101660025A (en) * 2009-09-28 2010-03-03 洛阳Lyc轴承有限公司 Medium frequency induction hardening process of super large diameter bearing steel castings
CN110564924A (en) * 2019-10-30 2019-12-13 江苏聚源电气有限公司 Quenching and tempering and integral quenching process method for 40CrMnMo steel

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3948259B2 (en) * 2001-05-21 2007-07-25 株式会社豊田自動織機 Shoe for a swash plate compressor and manufacturing method thereof
CN101509063B (en) * 2008-12-24 2011-01-26 中信重工机械股份有限公司 Process for quenching hard-tooth surface canine tooth loop intermediate-frequency edge roller seating space
CN108286016A (en) * 2018-01-23 2018-07-17 合肥康之恒机械科技有限公司 A kind of mining drilling rod forged steel and preparation method thereof
CN110016619B (en) * 2019-05-28 2020-01-21 营口市特殊钢锻造有限责任公司 Mining high-strength wear-resistant material and preparation method thereof
CN110306113B (en) * 2019-07-24 2020-09-18 郑州煤机智能工作面科技有限公司 Cast steel material for sliding shoe and casting method
CN110306012A (en) * 2019-08-20 2019-10-08 郑州煤机智能工作面科技有限公司 A kind of ring gear surface induction hardening processing method
CN110408856A (en) * 2019-09-09 2019-11-05 郑州煤机智能工作面科技有限公司 A kind of founding materials and its casting method for coalcutter torque axis

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101660025A (en) * 2009-09-28 2010-03-03 洛阳Lyc轴承有限公司 Medium frequency induction hardening process of super large diameter bearing steel castings
CN110564924A (en) * 2019-10-30 2019-12-13 江苏聚源电气有限公司 Quenching and tempering and integral quenching process method for 40CrMnMo steel

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